The Study of RNA-Based Genetic Control
Ribonucleic acid (RNA) was, until recently, thought of as being relegated to the role of genetic middleman between DNA, the genome, and proteins, the workhorse of biology. However, the known roles of RNA in biology have been expanded dramatically with the discovery that RNA itself can impact DNA replication, transcription elongation, RNA processing, and translation initiation among other processes.
Riboswitches are untranslated RNA segments functioning as genetic control elements by binding a target metabolite and controlling the expression of genes associated with the biosynthesis or import of the target metabolite or a closely related molecule. Simply, a riboswitch is a naturally occurring aptamer appended to a gene express ion platform. Riboswitches are found in all three kingdoms of life and represent a fundamental and energetically conservative form of genetic control, yet this RNA-based genetic control mechanism was discovered only several years ago.